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Question Strange (?) secondaries in inelastic and quasi-elastic scattering  

Forum: Hadronic Processes
Date: 13 Jun, 2016
From: Eleni Petrakou <Eleni Petrakou>

Dear Geant4eurs, 

We are scattering protons off carbon, and as far as I can tell, quasi-elastic 
scatterings belong to inelastic ones in G4. 
Also, this seems to mean that the primary protons get killed in both cases. 

However, there are some questions arising here: 

1. If you please look at the first attachment, you will see the energy 
distributions of the secondaries coming out from the inelastics. 
At the high end of the protons, there is a small but distinct peak. 
This peak is very compatible with what's expected from the *primary* protons 
which excited the nucleus and continued their way. Also, it's hard to think 
of an inelastic process that would produce this distribution. 
Do you think these might be the surviving primaries, reclassified? If yes, 
then is there some mechanism for fishing them out? 

2. Independently of the answer to the previous question, what happens to 
projectile protons which cause a nuclear excitation and they continue on 
their way, leaving the nucleus to de-excite as it sees fit? 
The point here is that not all primaries die in the process of inelastics 
and quasi-elastics. Is this reflected in G4? Can we identify these surviving 
particles for what they are? 

3. How can the secondaries from quasi-elastics be tagged accurately, i.e. 
not as coming from inelastics? 

4. If you take a look at the second attachment, you will see the energies 
vs. exit angles of the secondary protons from inelastics. You will see 
that a very distinct and mysterious feature stands out. (What is it?) 

5. If you compare this plot to the first one, you will see that the edge 
of this feature corresponds to a rising peak at high energies of protons. 
Exactly the same apply to the secondary neutrons as well (no plots attached). 
Now, these two rising peaks look compatible with expectations from 
quasi-elastic scatterings. Is there some cut-off applied to quasi-elastics 
which would explain this unexpected feature? 


Kamsahamnida, 
Eleni 




   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/06/13/19.17-15992-1__Inel_sec_E.png
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2016/06/13/19.17-59421-2__Inel_Pr_E_vs_Theta.png

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1 None: Re: Strange (?) secondaries in inelastic and quasi-elastic scattering   (Dennis H. Wright - 14 Jun, 2016)
1 Question: Re: Strange (?) secondaries in inelastic and quasi-elastic scattering   (Eleni Petrakou - 16 Jun, 2016)
2 None: Re: Strange (?) secondaries in inelastic and quasi-elastic scattering   (Eleni Petrakou - 27 Jun, 2016)
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